Separation of butadiene from hydrocarbon gases with cuprous chloride



July ll, 1950 E. v. MURPHREE v SEPARATION 0F BUTADIENE FROM HYDROCARBON GASES WITH CUPROUS CHLORIDE Original Filed March l, 1941 2 Sheets-Sheet 1 l' http;

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SEPARATION OF BUTADIENE FROM HYDROCARBON GASES WITH CUPROUS CHLORIDE Original Filed March 1, 1941 2 Sheets-Sheet 2 Patented July 11, 1950 SEPARATION OF BUTADIENE FROM HYDRO- CARBON GASES WITH CUPROUS CHLORIDE Eger V. Murphree, Summit, N. J., assig'nor to Standard Oil Development Company, a corporation of Delaware Original application March 1, 1941, Serial No. 381,294, now Patent No. 2,446,076, dated July moving certain constituents of such gases.

27, 1948. Divided and this application December 31, 1946, Serial No. 719,404

2 Claims. (Cl. 2611-6815) 'I'his invention relates to the separation and purification of gases wherein the gases are treated with a finely-divided adsorbent material and pertains more particularly to a. process of and apparatus for selectively removing certain gaseous constituents from a gas mixture.

The invention finds application in many industrial processes, such as recovery of solvent vapors from air in dry cleaning and painting establishments, drying of air .as in air conditioning, recovery of benzene and other aromatics from coal and coke oven gas', recovery of butane and other higher boiling hydrocarbons from natural and casinghead gas and separation of higher boiling hydrocarbon vapors from lower boiling hydrocarbons by selective adsorption or absorption. Other applications of this type will suggest themselves to those skilled in the art.

In connection with the above-named processes, it has previously been proposed to contact gases to be purified or separated with a solid adsorbent material capable of selectively adsorbing or re- The adsorbent material after being saturated with adsorbed or absorbed gases is thereafter treated to remove the adsorbed materials contained therein. The removal may be accomplished ,by heating to distill the adsorbed gases. The removal of such gas may be further expedited by use of a stripping gas in lieu of or in addition to the heating step.

Two general types of processes have heretofore been proposed to-obtain these results. According to one of the general types of operation, the gases to be treated are passed through a treating zone containing a fixed mass of adsorbent material and the passage of the gases is continued until the adsorbent material is more or less saturated with adsorbed gases. After this, the operation is interrupted. the adsorbedgases expelled from the material, and the process again resumed.

One serious objection to this type of process from an economic viewpoint is the necessity of frequently interrupting the flow of gases in order to remove adsorbed constituents from the adsorbents. In order to operate the process in a continuous manner, it is necessary to provide a plurality of treating chambers so that the stream of gases being treated can be transferred from one chamber to another when it becomes necessary to remove the adsorbent gases from the adsorbent medium.

proposed to introduce the adsorbent material into the stream of gases to be treated and to pass the resulting stream through a treating zone. Following this the adsorbed material is separated from the unadsorbed gases and adsorbent material treated 'in' a separate zon'l to remove the constituents adsorbed therein and the stripped adsorbent material then returned to the treating zone. While this method of operation avoids many of the objections to the discontinuous process of the type previously mentioned, it is nevertheiess open to other serious objections which have prevented its general adaptation on an extensive commercial scale. One of the serious objections to this type of operation is the difficulties involved in circulating the finely-divided adsorbent material through the system.

Perhaps one of the most serious difficulties encountered in operating a continuous process of this character is the provision of mechanism for building up sufficient pressure to feed the finelydivided material into the stream of gases to be treated. First of all, the pressure on the gases passing through the treating zone must be at least suillcient to overcome the pressure drop through the apparatus, which in turn will depend on a number of factors, perhaps the most important of which is the velocity of the gases passing through the system. One of the most common means employed heretofore for reintroducing the powdered adsorbent material into the gaseous stream is the use of a mechanical conveyor such as a compression screw. Such a conveyor, however, has not proven entirely satisfactory for use on adsorbent materials of this character due to the erosion and abrasion of the screw by the adsorbent material. Furthermore. the power consumption for driving the screw increases disproportionately with increase in pres- In view of the inherent objections to discontinuous processes of this type, it has also been tion hereinafter. For a better understanding of sure. For example, a twofold increase in pressure drop across the screw results in more than a twofold increase in power consumption necessary to drive the screw.

In view of these and other factors, continuous processes of the character heretofore mentioned have not found extensive favor for the purification and segregation of gases.

The object of the present invention is to provide a. continuous process and apparatus for the segregation and purification of gases by selective adsorbents which will not be subject to the objections herebefore noted.

Other objects and advantages of the invention will be apparent from the more detailed descripthe invention, reference will be made to the accompanying drawing wherein Figure 1 is a diagrammatic illustration of one form of apparatus suitable for carrying the invention into effect and Figure 2 is a modied form of the apparatus for carrying out a second embodiment of the invention.

Referring to Figure 1 of the drawing, the reference character 9 designates a charge linethrough which the gas to be treated or purified is introduced into the system. As previously mentioned, this gas may be any type of gas which is desire/d to be purified, refined or otherwise treated with solid material for the selective removal of certain constituents thereof. f Y Returning to the drawing, a part or.al1 of the gas is introduced and passed through line 9 to a mixing chamber I I in which it is admixed with a solid adsorbent material which may be ofthe nature of oxide gel, activated carbon, adsorbent clays, or the like. This product is preferably in finely-divided form, capable of selectively adsorbing the certain constituents from the gases. The mixture of gas and adsorbent material is then passed from mixing chamber II through line I2 having a heat exchanger I3 to a treating chamber I4 in which the powdered material is intimately vmixed with the gases to be treated.

In case the adsorbing agent introduced into the mixing chamber II is in highly heated condition, such as in the case when the adsorbing agent is freshly separated from the stripping gas or has been subjected to regeneration, the heat exchanger I3 may be used to cool the mixture to the desired temperature for absorption, In other cases where the adsorbing agent and gas to be treated are relatively cool as in starting the process, the heat exchanger I3 may be used for heatlng the mixture.

One of the important features of the present invention is thev passage of the mixture of adsorbent material and gases through the adsorbent chamber at a relatively low velocityso that there is a tendency for the powdered adsorbent material to settle or separate from the gases. However, the rate of iiow of the gases is greater than the rate of settling so that the tower never becomes completely packed with powdered material.

By operating in this manner, an intimate and continuous intermingling of the adsorbent solids and gases is attained. Furthermore, the residence time of the adsorbent material within the adsorber may be regulated over a wide range so as to insure complete saturation of the adsorbent material before removal from the chamber. It will be understood. however, that the residence time of the adsorbent material within the adsorber I4 will usually be considerably greater than the residence time of the gases within the chamber. For example, the time required for passage of the adsorbent material vthrough the adsorber-may range from seconds to one hour or more, whereas the time required for the passage of the gases through the chamber may be of the order of from 2 seconds to 10 minutes. Expressed in other words, the density of -the gases and the powdered material within the adsorber I4 is normally greater than the density of the 'stream passing to and from said chamber. To insure distribution of the gases and the solid material throughout the adsorber, the chamber may be provided with distributing platel5 having spaced perforations through which the suspension of solids and gases passes.

v4r sorber I4 are transferred through line I6 to a suitable separator such as a cyclone separator I1 for removing dust or other solids from gases.

The gas after passing through the initialseparator I1 is withdrawn through line I3 and, if desired, may be passed to additional separators (not shown) for further purification before being vented from the system.

Adsorbent material separated from the gas in the separator I1 feeds by gravity into the top of a standppe or tower 22 from which it may be returned to the adsorber as later described or into a second standppe 23 from' which it may be passed to a stripping zone to be later described. The height of the tower 22 is suilicient to develop a static pressure of powder at the bottom thereof sufficient to feed the adsorbent material into a stream of gases being recycled to the heat exchanger I3 and adsorber I4. In other words, the head of adsorbent material maintained in the vertical column 22 yshould be sumcient to develop a pressure at the bottom thereof which will overcome the pressure drop through the heat exchanger I3, adsorber I4 and the connecting lines. In order to transmit the pressure through the adsorbent material mass in the column 22, it is essential that the mass contained therein be in a vfreely owing, fluidized condition. To insure this,

a iiuidizing gas may be introduced at any one or more spaced points along the length ofthe tower through line 24 having branched lines 25, 26, 21, 28 and 29, respectively. The adsorbent material from the bottom of the standppe 22 may be fed into a mixing chamber 3| from which it may be remixed with wet gas to be treated .which is introduced into the mixing chamber through line 32. The resulting mixture of wet gas and recycled adsorbent agent passes through line 33 to the heat exchanger I3vwhere it intermixes with additional wet gas introduced through line I0. Adsorbent material collected in the standppe 23 discharges from the bottom thereof into a mixing chamber 34 wherein it admixes with a suitable inert stripping gas such as steam, carbon dioxide, spent combustion gases, or the like introduced into the mixing chamber through line I0. The height of the standppe 23 which charges the adsorbent material into the stripping gas should be of a height sufficient to develop a pressure at the bottom thereof which will feed the solid contact material into the stripping gas which in turn must be undera pressure at least suilicient to pass the resulting mixture through the stripping zone and related equipment. A iiuidizing gas may be introduced from a main line I at any one or more spaced points through inlet lines 2, 3, 4 and 5 along the vertical column 23 to maintain the adsorbent material in freely flowing condition as in the case of column 22.

The mixture of adsorbent material and stripping gas passes from 'the mixing chamber 34 through line 35 to a heat exchanger 36 wherein the mixture is heated to a temperature sufficient to liberate gases adsorbed on the adsorbent material during passage through the adsorber I4. The heated products from the heat exchanger 36 then pass through line 31 to a stripping chamber 38 whereinthe adsorbent material is retained for a period suiiicient to' distill or strip the adsorbent material of the adsorbed products.

The velocity of the carrier gas through the stripping chamber 38 is controlled as previously described in connection with the adsorber I4 so that the adsorbent material travels at a mate- 'I'he products after passing through the ad- 'lo rially lower velocity than the gases. As a result,

there is a continuous lntermixing of gas and powder.

The mixture of gases and adsorbent material passes from the stripper 38 through line 39 into a suitable separator such as a cyclone separator 4| in which the bulk of the stripped adsorbent material is separated fromthe gases. e

Gases separated from the adsorbent material in the separator 4I are removed therefrom through line 42 and are passed to a suitable condenser 43 in which the stripping gas or adsorbed gases or both may be condensed. Products from the condenser 43 pass to a receiver 44 wherein liquid condensate separates from unvaporized gases. In cases where both the stripping agent and stripped vapors or gases are condensable to form non-miscible liquids as is the case of steam and oil vapors, practically all the products from line 42 will be condensed in condenser 43.

The products from the condenser 43 may pass to a receiver 44 in which the liquid separates from the uncondensed vapors or gases and separate liquid phases are separated into layers. Uncondensed gases are withdrawn from the receiver 44 through line 45 and may be rejected from the system or otherwise treated in any desired manner. The heaviest liquid layer separated inthe receiver 44, which may be water in case steam is used as a stripping agent, may be withdrawn from the bottom of the receiver through line 45. The lighter liquid, which may be the oil stripped from the wet gases, may be withdrawn from the receiver 44 through line 41.

Adsorbent material separated in the cylone separator 4I discharges into standpipe or vertical column 48 of a height at least suillcient to produce a head of pressure at the bottom which will permit feeding the absorbent material back into the mixing chamber Il where it meets a stream of wet gas passing to the adsorber I4.

In order to insure an even iiow of the powdered material through the vertical column 48, a fluidizing gas may be introduced at one or more spaced points along the length thereof by means of iluidizing gas system 49 and in the hopper section of the separator 4l.

If desired, a portion of the stripped adsorbent material from the vertical column or standpipe 48 may be recirculated through the heat exchanger 36 and stripper 38 to maintain therdesired temperature within the stripping chamber.

For example, a portion of the stripped adsorbing rr-aterial from tower 48 may be passed through line 5I to a mixing chamber 52 wherein it is picked up by a stream of gas introduced through line 53. The resulting mixture passes through line 54 which merges with line 35 carrying the fresh unstripped adsorbent material to the heat exchanger 35. By regulating the amount of stripped powder recycled through thel heater to the stripping zone, any amount of heat may be supplied at any desired temperature level without the application of external heat to the stripper.

In many types of operations it may also be desirable to subject some or all of the absorbent material to a reactiviating treatment to remove foreign deposits which may form on the material during the adsorbing operation.

Referring again to the drawings, a part or all of the stripped adsorbent material from column v48 may be passed through conduit 55 to a mixing chamber 56 and there intermixed with a regenerating gas such as air or' a mixture of air and diluent gas introduced into the mixing chamber through line 51. The resulting suspension is then passed through line 58 to a regenerating zone 58.v The velocity of the regenerating gas ilowing through the regenerating chamber 59 may be controlled in such a manner that the time of 1 residence of the adsorbent material ,within the reactor is considerably greater thanv the time of residence of the regenerating gas as in the case of the adsorber and stripping chamber. The length of time the adsorbent material "is retained in the regenerator should be suilcient to complete the regeneration and is usually at least twice the time required for the regenerating gas.

The regeneration may take the form o'f an oxidizing treatment, particularly when the adsorbent material is employed for removing hydrocarbons or other carbonaceous or sulphur-containing materials from gases at elevated temperatures.

The stream of regenerating gas and absorbent l material after passing through the regenerating chamber 59 may be passed through line 5I to a suitable separator 62 for separation of the regenerated adsorbent material from the regenerating gas. The regenerating gas may be rejected from the system through line 83. Regenerated material separated in cyclone separator 52 discharges into a vertical tower or standpipe 64 from which it passes to mixing chamber 85 and is remixed with a stream of gas to be treated introduced through lines 9 and 68. When the regenerating treatment is employed, the height of the tower 54 should be suilicient to form a head of pressure which will feed the adsorbent material into the stream ofwet gas which in turn must be under a pressure at least suiilcient to overcome the pressure drop through theadsorbing portion of the apparatus. A iluidizing gas may be introduced by means of fluidizing gas system 8 into the columnv 54 and the hopper above the column at one or more spaced points to maintain the powder therein in freely flowing' condition.

vIn many cases it may also be desirable to recirculate a portion of the regenerated material through the regenerator to add or subtract heat therefrom. To .this end a portion of regenerated material from column 54 may be passed through line 51 to a mixing chamber 68 where it is picked up by a carrier gas f romrline 69. The suspension of carrier gas and regenerated powder then passes through line ll'to a heat exchanger l2 where the temperature is adjusted. The suspension after passing through the heat exchanger is remixed with unregenerated powder and regenerating gas passing through line 58. In cases where the regeneration treatment .is strongly exothermic, heat may be extracted through heat exchanger 12. In other cases it may be desirable to supply heat to the regenerating zone.

In the embodiment shown in Fig. 1, the absorption of gases is accomplished in a single stage. In many cases it is desirable to subject the gases to successive-stage absorbing treatment. For example, it is diiiicult, if not impossible, to so control the absorbing process so as to carry out the gas treatment to completion and at the same time saturate the absorbent material before the stripping step. In view of this it may be desirable to carry out the nal absorbing treatment with freshly-stripped or freshly-regenerated powder under conditions such that the powder is not completely saturated. When operating in this manner, the powder recovered from the nally treated gases may be used in the initial or intermediate stages of the absorbing treatment with- 7 out intermediate stripping. As a further alternative, freshlystripped or freshly-regenerated for regenerating the powder has been omitted,

it being understood that such regenerating equipment, similar to that shown in Fig. 1. may

be employed if desired. f Referring now to Fig. 2, the reference character 99 designates a line through which the gases or vapors to `be treated are introduced into the system. The gas is introduced through line 99 and passes into a mixing chamber 9| in which it intermixes with stripped absorbent powder `introduced through standpipe 92. As previously described with reference to Fig. 1, the powdered material within the standpipe 92 should be maintained in freely iiowing state and the height of the column should be at least suiiicient to build up a static pressure equal to the pressure of the gases introduced into the mixing chamber 9|. This pressure must, in turn, be at least suflicient to overcome the ow resistance of the circuit through which the resulting suspension must The resulting suspension of gases and absorbent powder passes from mixing chamber 8| through line 93 to heat exchanger 94 in which the temperature is adjusted prior to passing to the first-stage absorber Il.

As mentioned with reference to Fig. l, the velocity of the gases passing through the absorbing chamber 99 is controlled to maintain a relatively dense phase of absorbent powder therein. In other words, the velocity of the gases is not suillcient to carry the powder through the reac'- tion chamber at substantially the same rate as is the case of the gases. As a result, the time required for the passage of the powder through the absorbing chamber is materially longer than the time required for the passage of the gases and these relative times can be controlled over extended ranges.

The time during which the powdered material is retained within the ilrst absorber may be regulated to more or less thoroughly saturate the f' powder prior to removal from the absorbing chamber.

The suspension of treated gas and absorbent powder passes from the nrst stage absorber 99 through line 9| to a suitable separator such as a cyclone separator 91 in which the absorbent powder separates from the gases. 'I'he powdered absorbent material separated in the cyclone separator 91 discharges into a standpipe 99 which is maintained in uidized condition by means of a suitable iiuidizing gas introduced through line 99 and suitable branch lines leading therefrom.

The absorbent powder, which is more or less saturated with absorbed gases, discharges from the bottom of the standpipe 99 into a mixing chamber 9| in which it admixes with a suitable stripping gas introduced through line 92. The resulting suspension of stripping gas and powder passes from mixing chamber 9| through line 99 into a heat exchanger 99 wherein it is heated to a temperature suillcient to distill or otherwise remove the absorbed gases contained therein. Products from the heat exchanger 94 are passed 8 through line 99 to wherein the absorbent powder is maintained for a period suiiicient to distill or vaporize the absorbent products' contained thereon.

Products from the stripping chamber 95 are thereafter passed through line 96 to a cyclone separatorV 91,' or other equivalent device, for the separation of stripped products from the absorbent powder. The velocity of the stripping gas passing through the stripping chamber 95 is preferably controlled to build up a dense phase within the stripping zone so that the residence time of contact of the'absorbent powder is fairly longer than the time of residence of the stripping gas within the stripping chamber. Returning again to the standpipe 99, if desired a portion of the contact material contained therein may be recycled to the heat exchanger 94 and the rst absorber 99 through line 99 to serve in controlling the temperature therein.

Returning now to the cyclone separator 91, stripped powder separated in cyclone separator 91 discharges into a standpipe 82 from which the powder is discharged from the bottom thereof into the mixing chamber 9| where it admixes with the gases to be treated. The height of the standpipe 92 can be sulcient to develop a pressure at the bottom thereof suiiicient to develop a pressure at least equal to the pressure of the wet gas introduced through line 99.

If desired, a portion of the powder from the Astandpipe 92 in which the powder is kept in a iluid condition by means of iiuidizing gas system may be passed through line |02 into a mixing `chamber |03 where it is picked up by a stripping gas introduced through line |00. The resulting mixture of stripping gas and stripped powder may be passed through line |05 to heat exchanger 94 wherein it admixes with unstripped iigwder and stripping gas introduced through line der from the standpipe 92 may be withdrawn therefrom through line I 06 and passed to suitable regenerating equipment (not shown). Such regenerating equipment may, for example, comprise the type of apparatus illustrated in Fig. 1, or it may comprise other suitable means for reactivating the powder.

Also, a portion of the powder from the standpipe 02 may be withdrawn through line |08 and passed to a stream of gases being introduced into the second-stage absorber as hereinafter described.

Returning again to ,the cyclone separator 8'1 which receives products from the flrst-stage absorber 95, gases separated therein are removedl from cyclone separator" through line H0. i

In accordance with this embodiment'l of the invention, the gases are passed from line ||0 into a mixing chamber lll where they are again ad- `mixed with freshly-stripped powder withdrawn "from cyclone separator Ill through line ||6 and a stripping chamber 95v Also, if desired, a portion of the stripped pow- I may be rejected4 from the system or treated in any desired manner outside the purview of the present invention. Absorbent-powder, separated f from the treated gases in the cyclone separator,

mixes with stripping gas introduced through line 15 ||2. In this case, the mixture of stripping gas and powder passes through line |23 to the heat exchanger 94 and stripping zone 95.

However, in accordance with the preferredembodiment of the invention, the powder collected in the standpipe ||1 is iirst utilized in the firststage absorber 85 before passing through the i stripping section of the equipment. To this end,

a part or all of the powder from the standpipe may be passed through line |24 to a mixing chamber |25 wherein it admixesvv with fresh gas to be treated introduced through line 80. In this latter case, a valve in the :bottom of standpipe 82 may be closed so as to prevent the introduction of freshly-stripped powder into the fresh g-as stream,.or a part of the freshly-stripped powder may be added to the wet gas inaddition to the powder introduced through line |25. While Fig. 2 illustrates only two absorbing stages, it will be understood that, if desired, an additional number of stages may be employed.

As previously mentioned, one of the important features of the modification shown in Fig. 2 is the passing of the fresh gases to fbe treatedin the invention, it will be understood that it em- -10 the purifying treatment back to the oxide by oxidizing treatment.

As another example, carbon ldioxide may be selectively removed from air, ilue gases,` or the like by treatment with iinely-divided sodiumcarbonate in the manner herein described.

Butadiene may be extractedfrom hydrocarbon gases by treatment with ilnely-divided cuprous chloride, either alone or on a suitable adsorptive carrier. In either case, regeneration may be accomplished by heating or by the use of a 'stripping gas or both. Alcohol vapors may be recov- `A`ered'from air or othergases using synthetic gels,

fullers earth, charcoal, and the like.

The above-named uses for the invention are given for illustrative purposes, `it being understood that other applications will occur to those skilled in theA art.

The terms adsorbents, adsorbent materials" and the like are intended to mean materials capable of retaining "considerable volumes of gases whether or not such retention is in fact accomplished by adsorption, absorption, occlusion, or other phenomena.

Having described the preferred -embodiment of braces s'uch other variations and modifications as come within the spirit and scope thereof.

This application forms a division of application Serial No. 381,294, illed March 1, 1941, which issued as Patent No. 2,446,076 on July 27, 1948.

What is desired to be protected by Letters Patent is:

1. A continuous process for treating a gaseous hydrocarbon mixture to remove butadiene therefrom, which comprises suspending nely-divided cuprous chloride in said gaseous mixture containing butadiene, passing the resulting suspension upwardly into a treating zone wherein the Contact With partially Sed DOWdeI' and then' 40 cuprous chloride is maintained as a dense turbu- -stripped product from the cyclone separator 91 may be passed through line |26 to va condenser |21 wherein the stripped gases, stripping gas, or both products may be condensed. The resulting products are then passed to a suitable receiver,

such as shown in Fig. l, for segregation of the stripped products from the stripping gas. If desired, the stripping Sas may .be again reused in the system.

The present invention nds wide application in the purication and recovery of gases and vapors. In the foregoing embodiment the puriflcation has been accomplished -by physical adsorption or absorption of the impurities from the lent fluidized suspension and the butadiene is selectively removed from the gaseous mixture by lthe cuprous chloride, flowing the fiuidized suspension from an upper part of said treating zone 45 ,into a separation zone wherein said cuprous chloride retaining butadiene is separated from the rest of the treated gaseous mixture, transferring the separated cuprous chloride with butadiene retained thereby in a free ilowing stream from the separation zone into a stream of inert stripping gas, passing the resulting suspension of cuprous chloride with retained butadiene in the inert stripping gas up through an indirect heat exchange zone where the thus suspended cuprous chloride is heated, withdrawing the thus heated suspension from the indirect heat exchange zoneI passing the heated suspension of cuprous chloride in the inert -stripping gas upwardly through a stripping zone wherein lthe gases Purification may also be obtained accord do butadiene is stripped from the cuprous chloride,

ing to the present invention by contacting the gases to, be puriiied or otherwise treated with a solid material capable of reacting with the ixnpurities to form .new compounds. Such treating processes may involve, for example, the removal of hydrogen sulde from gases by treating the gases'with a solid alkaline or alkaline earth hydroxide supported on a suitable inert carrier. Such puriilcation may also be obtained by treating the hydrogen sulfide-containing gases with ferric oxide, nickel oxide, or copper oxide supported on a carrier if desired. In such cases, regeneration can be accomplished by reconverting the nickel. copper, or ferrie sulnde resulting from 75 separating the butadiene with the inert stripping gas from the stripped cuprous chloride and returning the stripped cuprous chloride to said treating zone.

2. The process as described in claim l, in which the stripped cuprous chloride is returned to the treating zone by being suspended in the gaseous hydrocarbon mixture containing butadiene, and said gaseous hydrocarbon mixture with the cuprous chloride .suspended therein is passed through a heat exchange zone before being passed upwardly into the treating zone.

EGER V. MURPHREE.

(References on following page) n 'En f 12` Y REFERENCES CIT t 1 Y nonmm PATENTS J The following references arg o vrecord in the l Number, country Date i 111e of this patent.

. 533,037 AC'vermany Sept. 8, 1931 .UNITEDBTATESPAI'ENTS o v' Number Name Date v M 1HE REI ERENCES l 1,577,534" lMiller Mar. 23, 1926 Lure et al., Sinteticheskii-Kauchuk, 1934, Nn. 6, 1,825,707 Wagner Oct. 6, 1931 pages 19-29. y A-35 page translation of this article 2,270,903 Rudbach f Jan. 27, 1942 1S in Division 31. v 2,336,643 Schulze Dec. 14, 1943 10 Gilliland et al., J. A. C. S., vol. 63, pages 2088- A2,386,734 Wolk Oct. 9, -1945 2090,- August 1941.

2,446,076 Campbell et l. ,July 27, 1948 I v 2,451,804 Campbell et' al Oct. 19,1948 

1. A CONTINUOUS PROCESS FOR TREATING A GASEOUS HYDROCARBON MIXTURE TO REMOVE BUTADIENE THEREFROM, WHICH COMPRISES SUSPENDING FINELY-DIVIDED CUPROUS CHLORIDE IN SAID GASEOUS MIXTURE CONTAINING BUTADIENE, PASSING THE RESULTING SUSPENSION UPWARDLY INTO A TREATING ZONE WHEREIN THE CUPROUS CHLORIDE IS MAINTAINED AS A DENSE TURBULENT FLUIDIZED SUSPENSION AND THE BUTADIENE IS SELECTIVELY REMOVED FROM THE GASEOUS MIXTURE BY THE CUPROUS CHLORIDE, FLOWING THE FLUIDIZED SUSPENSION FROM AN UPPER PART OF SAID TREATING ZONE INTO A SEPARATION ZONE WHEREIN SAID CUPROUS CHLORIDE RETAINING BUTADIENE IS SEPARATED FROM THE REST OF THE TREATED GASEOUS MIXTURE, TRANSFERRING THE SEPARATED CUPROUS CHLORIDE WITH BUTADIENE RETAINED THEREBY IN A FREE FLOWING STREAM FROM THE SEPARATION ZONE INTO A STREAM OF INERT STRIPPING GAS, PASSING THE RESULTING SUSPENSION 